同种异体带瓣管道重建右心室流出道耐久性研究现状

早在1966年已有报道用同种异体带瓣管道(valved homograft conduit，VHC)连接右心室(RV)到肺动脉(PA)，为复杂心脏畸形提供了新的手术方法。但因VHC来源、保存方法及管道早期梗阻等问题，曾被放弃使用。而带异种瓣的人工血管虽来源丰富、尺寸齐全而被广泛应用，但其长期效果不理想。此后，欧洲采用抗生素，营养液保存VHC。自20世纪80年代末，美国开始采用低温保存技术，基本解决了VHC保存等问题，不断改善VHC的耐久性(durability)。     

肺动脉带瓣管道重建右心室流出道

目的 总结多中心临床试验采用佰仁思(BalMedic)肺动脉带瓣管道(以下简称带瓣管道)作为右心室流出道重建的临床试用情况和随访结果.方法 2007年1月至2010年10月,多中心的50例复杂先天性心脏病患儿(者)采用佰仁思肺动脉带瓣管道,男23例,女27例;年龄6个月～ 39岁,平均(4.90 ±7.63)岁;体质量4.50 ～ 65.00 kg,平均(16.20±13.69) kg.病种包括肺动脉闭锁伴室间隔缺损22例,纠正型大动脉错位伴肺动脉狭窄10例,永存动脉干7例,右心室双出口伴肺动脉狭窄4例,法洛四联症3例,完全性大动脉错位伴肺动脉狭窄2例,肺动脉狭窄和主动脉瓣狭窄伴关闭不全各1例.取相应大小的带瓣管道,重建右心室与肺动脉的连接.患儿(者)术后1个月、3～6个月和≥12个月,接受心脏超声复查,并填写随访表.结果 患儿(者)手术无死亡.术后随访≥12个月者中3例失访,1例死亡.肺动脉瓣环无狭窄率91.1％,中度反流率16.0％,右心室流出道无狭窄率95.6％,主肺动脉无狭窄率80.O％,左、右肺动脉无狭窄率73.3％.结论 多中心临床试验结果表明,佰仁思(BalMedic)肺动脉带瓣管道的有效性和安全性可满足临床治疗要求,中长期疗效有待进一步随访和观察.     

国产牛颈静脉带瓣管道重建右室流出道临床应用

目的总结国产牛颈静脉带瓣管道在右室流出道重建手术中的应用和术后早期临床随访结果。方法2004年2月至2005年3月，14例病人（男6例，女8例；年龄5个月～22岁；体重8～40k）使用了完整牛颈静脉带瓣管道重建右室流出道。记录术后并发症，术后1个月用心脏超声对移植的牛颈静脉进行功能评价。结果住院期间均无栓塞等带瓣管道相关并发症发生，恢复顺利，出院。术后1个月超声检查示重建的右室流出道通畅，4例移植管道存在轻度瓣膜反流。结论国产牛颈静脉带瓣管道易于获取，型号较齐全，移植后早期临床疗效满意，可作为一种右室流出道重建的替代材料，但其中、远期疗效仍须持续随访观察。     

同种带瓣大动脉重建右心室流出道

目的：应用自行采集和冷冻保存的同种带瓣大动脉（VHC）完成先天性心脏病右心室流出道的重建,并观察其疗效及存在的问题。方法：用VHC材料治疗先天性心脏病95例,90例手术根治,5例行VHC右心室流出道与肺动脉连接姑息手术。结果：院内死亡13例,术后随访68例,死亡2例,均为感染,66例长期生存者中25例胸部X线片示VHC有钙化,多淡主动脉材料,仅5例有轻中度压力阶差（35－60mmHg)。结论：VHC可广泛用于治疗复杂先天性心脏病,程序降温,超低温保存和两步化冻是VHC使用质量的保证,VHC的长期通畅比合成管道好,随植入时间延长钙化率增加,肺动脉VHC优于主动脉,有肺动脉高压者宜尽早手术,为了预防VHC植入后感染,应重视,改善其收集和保存的方法。     

牛颈静脉带瓣补片在复杂先天性心脏病患者右心室流出道重建中的应用

目的评价牛颈静脉带瓣补片应用于重建右心室流出道的近期效果。方法回顾性分析2009年5月至2010年3月武汉亚洲心脏病医院行牛颈静脉带瓣补片重建右心室流出道60例患者的临床资料,男42例,女18例;年龄5个月～33(6.2±8.9)岁,其中34例<1岁;体重(27.5±24.0)kg。术前临床诊断为法洛四联症38例,右心室双出口合并肺动脉狭窄22例。所有患者均行一期完全修复术,有4例因为侧枝循环较多,术前采取介入侧枝封堵。全组患者肺动脉瓣瓣环直径均小于正常值2个标准差,均采取跨瓣环补片重建右心室流出道。随访时间18～26(21.2±4.6)个月。结果手术无死亡,也无因流出道严重狭窄和严重肺动脉瓣反流需再次手术者。有3例患者术后早期因为侧枝循环较多,拔除气管内插管后出现肺水肿,再次气管内插管;4例患者因出血需二次开胸止血,其他患者术后均顺利康复出院。体外循环时间(84.0±22.0)min,主动脉阻断时间(42.0±12.0)min。术后即刻右心室流出道压力阶差(18.0±4.5)mm Hg,术后最后一次随访的经胸超声心动图检查提示,右心室流出道压力阶差为(19.2±5.4)mm Hg,两者差异无统计学意义(P>0.05)。术后即刻肺动脉瓣反流程度:轻微反流32例(1+),轻度反流28例(2+);术后最后一次随访的经胸超声心动图检查提示,反流程度:轻微28例(1+),轻度27例(2+),中度5例(3+);两者反流程度差异无统计学意义(P>0.05)。牛颈静脉带瓣补片及瓣叶组织均未见钙化,瓣叶活动良好。无牛颈静脉血栓形成及感染性心内膜炎发生。结论对法洛四联症和右心室双出口合并肺动脉狭窄的患者,牛颈静脉带瓣补片是右心室流出道跨瓣环重建的一种良好材料,无相关的严重并发症发生,近期右心室流出道压力阶差没有明显增加,肺动脉瓣抗反流性能良好;远期效果还需进一步随访观察。     

同种带瓣大动脉重建右心室流出道术后护理

对164例复杂先天性心脏病患者采用同种带瓣大动脉（VHC）重建右心室流出道术。结果术后8～42h拔除气管插管，ICU滞留时间3～80d，除20例死亡外，其余均康复出院，出院时心功能均为Ⅰ级。随访3个月至10年，仅1例因。VHC感染死亡，其余心功能良好。表明术后对呼吸、循环、泌尿和神经系统的严密监护是手术成功的重要环节。     

自体带蒂带瓣心包片在右心室流出道重建中的应用

2001年12月至2003年10月,我们对63例法洛四联症根治术病儿分别应用自体带蒂带瓣心包片、带自体心包单瓣的人工补片和单纯自体心包片进行右心室流出道重建,并随访2年.现就自体带蒂带瓣心包片在右心室流出道重建中的应用价值报道如下.     

自体带瓣心包片在右心室流出道重建中的应用

目的 评价自体带瓣心包片在右心室流出道重建中的应用价值。方法 18例先天性心脏病患者行右心室流出道重建手术，术中采用带心包瓣的自体心包片扩大右心室流出道，直径大小按体重和年龄而定，用一块“Δ↓”形的心包片作为右心室流出道的瓣膜，其长短为肺动脉瓣口至右心室切口的最低点。术后随访15例，随访时间3～24个月，采用彩色多普勒超声心动图检测瓣膜的远端、近端和瓣膜水平的流出道直径和压差的大小。结果 术后无死亡患者，出院前复查，5例有轻度肺动脉瓣反流；经24个月复查，9例患者重建的肺动脉(瓣膜水平)直径增加1．0～2．5mm，4例无变化，2例减小1．0～1．5mm，3例失随访；随访中无需再次手术患者。结论 采用自体带瓣心包片重建右心室流出道不需长期抗凝，操作容易、简便，随着时间推移组织能生长，再次手术率也较低。     

丁二醇改性戊二醛鞣制的牛颈静脉带瓣管道重建犬右室流出道

戊二醛固定的生物材料存在易钙化，具有细胞毒性作用及耐久性差等缺点，我们用2，3-丁二醇对戊二醛固定的牛颈静脉改性处理，将其连接于犬的右室-肺动脉间进行长期观察，旨在评价这种改性方法对血流动力学性能的影响。     

同种异体带瓣管道重建右室流出道的耐久性随访研究

目的探讨深低温保存的同种异体带瓣管道（valved homograft conduit，VHC）在重建小儿右室流出道（right ventricular outflow tract，RVOT）中耐久性情况，及影响其耐久性的危险因素。方法1989年11月至2003年7月用VHC重建RVOT，随访65例次临床情况、心电图、X线胸片、心脏超声和心脏MRI。借此了解病儿体内VHC钙化、梗阻和反流情况。用现代统计方法分析影响VHC耐久性的危险因素。结果65例次中VHC中位生存时间10．9年，管道生存最长时间12．8年。结论小年龄（≤4岁）、低体重（≤10kg）和主动脉VHC是影响VHC耐久性的危险因素。     

牛颈静脉带瓣管道重建犬右心室流出道的血流动力学研究

目的观察自制牛颈静脉带瓣管道重建犬右心室流出道后的血流动力学性能. 方法应用经戊二醛处理的牛颈静脉带瓣管道对7只犬行肺动脉与右心室连接,重建右心室流出道前后测定肺血流动力学,行超声心动图检查牛颈静脉带瓣管道通畅情况. 结果重建术后1年7只犬均存活.重建右心室流出道前后肺动脉收缩压、舒张压和平均压均无明显改变,右心室舒张压无明显变化,收缩压和平均压显著增加(P<0.01).术后超声心动图检查瓣膜关闭良好,无明显反流,跨瓣压差小;术后1年超声心动图检测发现全部带瓣管道通畅,未见明显血栓形成,除1只犬瓣叶活动稍差合并轻度反流外,其余犬瓣叶活动良好.心导管测压显示肺动脉与右心室之间压差为3～19 mm Hg(1kPa=7.5mmHg),管道内舒张压显著高于右心室舒张压,右心室造影显示牛颈静脉带瓣管道和肺动脉无明显梗阻.结论戊二醛处理牛颈静脉带瓣管道重建右心室流出道具有良好的血流动力学性能.     

异种牛颈静脉带瓣管道重建右室流出道研究

目的 观察去细胞牛颈静脉带瓣管道( BJVC)重建猪右心室流出道后的细胞生长特性、抗钙化性能及血流动力学性能.方法 应用经去细胞、鞣制、改性(B组,n=8)及未去细胞(A组,n=8)的BJVC分别进行猪肺动脉与右心室连接,行光镜及电镜观察宿主内皮细胞及肌成纤维细胞生长特点,原子火焰法检测组织钙含量,超声心动图检测 BJVC 血流动力学参数.结果 术前A组BJVC试片表面无内皮细胞,术后12个月内膜表面50％～60％的表面覆盖卵圆形内皮细胞,基质层未见宿主成纤维细胞迁入;术前B组去细胞后BJVC已基本无细胞成分,术后12个月内皮细胞覆盖率约80％ ～90％,宿主肌成纤维细胞已爬行迁移至基质层的1/3.术后A组近端及远端吻合口管壁、瓣膜组织钙含量显著大于B组(P＜0.05),B组上述各项指标均显著大于新鲜BJVC(P ＜0.05).术后当天A组及B组各项血流动力学指标比较差异无统计学意义(P＞0.05),B组术后当天及术后12月各项指标比较差异无统计学意义(P＞0.05);术后12月A组远端吻合口口径显著小于B组(P＜0.05),远端吻合口压差、跨瓣压差、牛颈静脉返流量显著大于B组(P＜0.05).结论 去细胞化后鞣制、改性的牛颈静脉是一种更好的重建右室流道材料,但远期效果需进一步研究.     

Late results of right ventricular outflow tract reconstruction with a bicuspid expanded polytetrafluoroethylene valved conduit

Background and Aim to Read

We report the results of a bicuspid expanded polytetrafluoroethylene (ePTFE) valved conduit used for right ventricular outflow tract reconstruction (RVOTR).

Methods

Between November 2005 and February 2009, 12 conduits were used for RVOTR. The mean age and weight of patients were 43.5 ± 46.4 months and 13.4 ± 8.6 kg. The main diagnosis was tetralogy of Fallot with pulmonary atresia in eight patients. The most common conduit size was 18 mm. The mean follow‐up was 88.0 ± 35.9 months.

Results

There were no operative and late mortalities. At discharge, the mean peak systolic pressure gradient across the RVOT was 14.1 ± 11.3 mmHg. There was no conduit valve regurgitation in nine patients. At the latest echocardiography (mean follow‐up: 84.3 ± 35.5 months), the mean peak systolic pressure gradient across the RVOT was 59.7 ± 20.2 mmHg, and there was no conduit valve regurgitation in six patients. Freedom from conduit malfunction was 100% and 83.3%, at 1 and 8 years, respectively. Two conduits were explanted due to sternal compression and four from conduit malfunction. Freedom from explantation was 83.3% and 74.2% at 2 and 8 years, respectively.

Conclusions

ePTFE bicuspid valved conduit has good late function in terms of valve regurgitation, but the pressure gradient across the conduit increases with time, which is the main cause of conduit failure and explantation.     

In vitro evaluation of right ventricular outflow tract reconstruction with bicuspid valved polytetrafluoroethylene conduit

Conduits available for right ventricular outflow tract (RVOT) reconstruction eventually become stenotic and/or insufficient due to calcification. In order to reduce the incidence of reoperations we have developed and used a bicuspid valved polytetrafluoroethylene (PTFE) conduit for the RVOT reconstruction. The purpose of this study is to investigate the hemodynamic performance of the new design using a pediatric in vitro right heart mock loop. PTFE conduit has been used for the complete biventricular repair of 20 patients (age 1.7±6 years) with cyanotic congenital defects. To account for the large variability of conduit sizes, 14, 16, 22, and 24-mm conduit sizes were evaluated using an in vitro flow loop comprised of a pulsatile pump with cardiac output (CO) of 1.2-3.2L/min, bicuspid valved RVOT conduit, pulmonary artery, venous compartments, and the flow visualization setup. We recorded the diastolic valve leakage and pre- and post-conduit pressures in static and pulsatile settings. In vitro valve function and overall hemodynamic performance was evaluated using high-speed cameras and ultrasonic flow probes. Three-dimensional flow fields for different in vivo conduit curvatures and inflow regimes were calculated by computational fluid dynamics (CFD) analysis to further aid the conduit design process. The average pressure drop over the valved conduits was 0.8±1.7mm Hg for the CO range tested. Typical values for regurgitant fraction, peak-to-peak pressure gradient, and effective office area were 23±2.1%, 13±2.4mm Hg, and 1.56±0.2 cm(2) , respectively. High-speed videos captured the intact valve motion with asymmetrical valve opening during the systole. CFD simulations demonstrated the flow skewness toward the major curvature of the conduit based on the pulmonic curvature. In vitro evaluation of the bicuspid valved PTFE conduit coincides well with acceptable early clinical performance (mild insufficiency), with relatively low pressure drop, and intact valve motion independent from the conduit curvature, orientation or valve location, but at the expense of increased diastolic flow regurgitation. These findings benchmark the baseline performance of the bicuspid valved conduit and will be used for future designs to improve valve competency.     

Mid-term outcomes of Contegra implantation for the reconstruction of the right ventricular outflow tract to proximal branch pulmonary arteries: Japan multicentre study

Open in a separate window OBJECTIVESTo reveal the mid-term outcomes of Contegra implantation for the reconstruction of the right ventricular outflow tract to proximal branch pulmonary arteries in a multicentre study. METHODSBetween April 2013 and December 2019, 178 Contegra conduits were implanted at 5 Japanese institutes. The median age and body weight at operation were 16 months (25th–75th percentile: 8–32) and 8.3 kg (6.4–10.6). Sixteen patients were neonates (9.0%). Selected conduit sizes were 12 mm in 28 patients (15.7%), 14 mm in 67 patients (37.6%), 16 mm in 66 patients (37.1%), 18 mm in 5 patients (2.8%) and <12 mm in 12 patients (6.7%). Fifty-six grafts (31.4%) were ring supported. Proximal branch pulmonary arteries were concomitantly augmented in 85 patients (47.5%). Follow-up was completed in all patients and the median follow-up period was 3.1 years (1.3–5.1).RESULTSThe overall, conduit explantation-free and conduit infection-free survival rates at 5 years were 91.3%, 71.0% and 83.7%, respectively. Infection (P = 0.009) and common arterial trunk (P = 0.024) were risk factors for explantation. Conduit durability was shorter in smaller one (P < 0.001). Catheter interventions (for conduit to proximal branch pulmonary artery)-free survival rates at 5 years was 52.9%; however, need for catheter interventions was not a risk factor for conduit explantation.CONCLUSIONSMid-term outcomes of reconstruction of the right ventricular outflow tract to the proximal branch pulmonary arteries with Contegra were acceptable. The need for explantation over time was higher in smaller conduits. Conduit infection was a strong risk factor for conduit explantation. Frequently and repeated catheter interventions effectively extended the conduit durability.     

Long-term outcome of right ventricular outflow tract reconstruction with bicuspidalized homografts

Objective: Given the shortage of small-sized cryopreserved homografts for right ventricle (RV) to pulmonary artery (PA) reconstructions, more readily available larger-sized homografts can be used after size reduction by bicuspidalization. The aim of our study was to determine and compare function over time of standard and bicuspidalized homografts in infants younger than 12 months, including patients with a Ross or extended Ross procedure. Methods: All consecutives infants under the age of 1 year, who underwent a surgical procedure in which a homograft was placed in the RV-PA position between January 1994 and April 2009, were included. Prospectively collected data from serial, standardized echocardiography from all patients were extracted from the database, and hospital records were retrospectively reviewed. Results: A total of 40 infants had a valved homograft conduit placed in the RV-PA position. In 20 of those patients, a bicuspidalized homograft was used. Twelve patients underwent a Ross procedure, of whom seven had an additional Konno-type aortic annulus enlargement. Median follow-up was 146 months (interquartile range (IQR), 117–170; total patient years: 178) in the group with standard use of the homograft and 95 months (IQR, 11–104; total patient years: 78) in the group with bicuspidalized conduits. Freedom from re-intervention (re-operation or percutaneous) was not different in the standard and bicuspidalized groups for all and Ross or Konno–Ross procedures (Tarone-Ware, p = 0.65 and p = 0.47, respectively). Consecutive echocardiographic maximum velocities in the right ventricular outflow tract were similar in the standard and bicuspidalized groups. Conclusion: When proper sized cryopreserved homografts for placement in the RV-PA position in Ross, Konno–Ross, and other procedures in infants under the age of 1 year are not readily available, bicuspidalized homografts provide an acceptable alternative.     

Intracardiac hydatid cyst located in right ventricular outflow tract: a rare site

Intracardiac hydatid cyst is relatively uncommon and involvement of right ventricular outflow tract is extremely rare. We report a rare case of intracardiac hydatid cyst involving the right ventricular outflow tract and do a review of literature.     

Reconstruction of right ventricular outflow tract with stentless xenografts in Ross procedure

To investigate whether the use of a stentless porcine aortic xenograft can be an alternative for right ventricular outflow tract (RVOT) reconstruction during the Ross procedure, 9 patients underwent the Ross procedure and RVOT reconstruction with a stentless xenograft since January 2000. After the aortic valve was replaced with a pulmonary autograft, a stentless xenograft with a xeno- pericardial roll was implanted in the RVOT. One patient required subsequent aortic valve replacement because of severe regurgitation of the pulmonary autograft. All patients recovered well from the operation. The right ventricle-pulmonary arterial pressure gradient was 18 +/- 7 mm Hg at discharge and was not significantly increased during the 2-year follow-up period. Although 1 patient died of ventricular arrhythmia 5 months after, his cardiac function was normal, and transpulmonary valve pressure was 19 mm Hg in the follow-up. The other 7 patients are currently in New York Heart Association functional Class I. Although long-term follow-up is required to explain the durability, the stentless xenograft with a pericardial roll is considered to be an alternative for reconstruction of the RVOT within 2 years after the Ross procedure.     

小儿永存动脉干右室流出道重建

目的 总结小儿永存动脉干(PTA)右室流出道重建治疗经验.方法 2000年1月至2007年12月共行PTA根治手术治疗43例,男26例,女17例.年龄1.5个月～3.8岁;体重3.2～23.0kg.Ⅰ型、Ⅱ型和Ⅲ型PTA分别为26例、11例和6例.18例PTA的肺动脉直接下拖至右室流出道切口上缘相吻合,前壁再用心包补片扩大;8例用Homograft管道、14例用牛颈静脉管道连接远端肺动脉和右心室,重建右室流出道;3例Ⅱ型者,肺动脉后壁用左心耳壁与右室流出道上缘做吻合,前壁再用心包补片扩大.结果 术后所有病儿均生存,5例表现为右心功能不全,2例右肺动脉(RPA)压差37.5～47.3 mm Hg(1mm Hg=0.133kPa),术后17d恢复至35.3mm Hg以下.左心室流出道阶差均小于20.3mm Hg.残余VSD(2mm)1例,乳糜胸1例.5例病儿肺血管阻力高,吸一氧化氮(NO)治疗7d左右后好转.随访3个月～3年,2例病儿RPA残余压差24.0～29.3 mm Hg,均无明显右心室或左心室流出道梗阻.结论 肺总动脉后壁直接与右心室切口作吻合重建PTA的右室流出道,早期和远期效果良好.牛颈静脉的带瓣管道的应用,解决了小尺寸同种带瓣管道来源不足的问题,操作简便.